1. Field of the Invention
The present invention generally relates to circular saw blades, and more particularly, is concerned with split circular saw blades which are aligned and joined by self-interlocking projections and recesses.
2. Description of the Prior Art
In many lumber mill operations, a "gang saw" is used, wherein a number of circular saw blades are attached to a single rotating shaft or arbor, in order to make multiple cuts on a single pass of the wood being cut. As many as fifty or more circular saw blades could be used on a single arbor. In order to replace a single circular saw blade, it initially was necessary to remove any blades to the outside of that blade, so that the blade being replaced could be slipped off of the end of the arbor. This process was time consuming and created unnecessary wear on the arbor. Subsequently, quick change "split saws" were developed where the circular saw blade was cut in half. These blades were directly replaceable at any position on the gang arbor by loosening their means of attachment to the arbor and removing the two pieces constituting the split blade.
While the advent of the split saw blade improved efficiency due to the reduction in time required to replace individual saw blades, it also resulted in significantly increased costs for both the saw blades themselves and the means of attachment to the arbors. One system modified the blades with a machined collar which fit into a circular recess machined into the back plate affixed to the arbor. Another design provided for multiple holes in each blade section which fit over studs attached to the back plate. These systems were expensive because of the machining required and often lacked the accuracy necessary for precise alignment of the blades on the arbor. In order to gain a measure of universality, some blades were manufactured with both a collar and stud holes.
There remains a need for a saw blade design which can find universal use on standard arbors, but with the advantage of the quick change split saws. Needed is a design which removes the recess collars on the arbor back plate and the collar ribs on saw blades, and eliminates the need for holes in the blades and the special machining of arbors. Also needed are saw blades which can be used on either left or right hand arbors, and which are easier to maintain than the current blades. And, finally, a split saw blade system which cost less to manufacture is needed.